Recently, as society has enters a full-scale information age, the field of displays for handling and displaying mass information has rapidly developed, and in response thereto, various flat panel displays have been developed and have received attention.
Independent examples of such flat panel display devices may include liquid crystal display (LCD) devices, plasma display panel (PDP) devices, field emission display (FED) devices, electroluminescence display (ELD) devices, and the like, and these are used in various fields, including the field of Information Technology in devices such as laptop computers, in the field of mobile communications in devices such as mobile phones, as well as in the field of consumer electronics in devices such as televisions and videos. Such flat panel display devices exhibit excellent characteristics in terms of thinning, lightening and reductions in the power consumption thereof, and have rapidly replaced cathode ray tube (CRT) displays that have been used in the art.
Particularly, OLED devices emit light by themselves and are capable of being operated at low voltages, and accordingly, have been adopted at a rapid pace in the area of small displays for products such as portable devices. In addition, OLEDs are facing commercialization beyond small displays in large televisions.
Meanwhile, flat panel display devices generally use glass materials in a substrate supporting the device and as an encapsulation layer preventing moisture penetration, and glass materials have limitations in allowing for lightening, thinning and flexibility. Accordingly, flexible display devices capable of maintaining a display function even when being bent like paper using flexible materials such as metal, plastic and polymer materials instead of existing glass encapsulants having no flexibility have recently emerged as next-generation flat panel display devices.
However, using encapsulants such as plastic or polymer materials in OLEDs has a disadvantage in that plastic or polymer materials have high moisture permeability and shorten a lifespan of OLEDs due to the penetration of moisture. In addition, there is a disadvantage in that heat generated inside display devices is not effectively released due to generally low heat dissipation efficiency, and improvements have therefore been required.
Meanwhile, metal encapsulants have a highly superior moisture preventing ability due to the nature thereof, and also have very excellent heat dissipation properties. However, preparing thin encapsulants using an existing rolling method has a disadvantage in that manufacturing costs rapidly increase as substrate thicknesses are reduced.
Accordingly, technologies for preparing metal encapsulants using an electroforming method have recently been proposed, and use of such an electroforming method is expected to be rapidly expanded due to its lower manufacturing costs compared to an existing rolling method.
However, while metal encapsulants prepared using an existing rolling method have a thickness of approximately 100 μm, metal encapsulants prepared using an electroforming method are formed to a thickness of 20 μm to 50 μm in order to secure the above-mentioned effects, and when the metal encapsulant is formed into an excessively thin film, the metal encapsulant has a disadvantage in that heat dissipation properties decline due to decreased heat capacity when heat generated inwardly thereof needs to absorbed by the metal encapsulant.